cpython/Include/internal/pycore_long.h

117 lines
3.5 KiB
C

#ifndef Py_INTERNAL_LONG_H
#define Py_INTERNAL_LONG_H
#ifdef __cplusplus
extern "C" {
#endif
#ifndef Py_BUILD_CORE
# error "this header requires Py_BUILD_CORE define"
#endif
#include "pycore_global_objects.h" // _PY_NSMALLNEGINTS
#include "pycore_runtime.h" // _PyRuntime
/*
* Default int base conversion size limitation: Denial of Service prevention.
*
* Chosen such that this isn't wildly slow on modern hardware and so that
* everyone's existing deployed numpy test suite passes before
* https://github.com/numpy/numpy/issues/22098 is widely available.
*
* $ python -m timeit -s 's = "1"*4300' 'int(s)'
* 2000 loops, best of 5: 125 usec per loop
* $ python -m timeit -s 's = "1"*4300; v = int(s)' 'str(v)'
* 1000 loops, best of 5: 311 usec per loop
* (zen2 cloud VM)
*
* 4300 decimal digits fits a ~14284 bit number.
*/
#define _PY_LONG_DEFAULT_MAX_STR_DIGITS 4300
/*
* Threshold for max digits check. For performance reasons int() and
* int.__str__() don't checks values that are smaller than this
* threshold. Acts as a guaranteed minimum size limit for bignums that
* applications can expect from CPython.
*
* % python -m timeit -s 's = "1"*640; v = int(s)' 'str(int(s))'
* 20000 loops, best of 5: 12 usec per loop
*
* "640 digits should be enough for anyone." - gps
* fits a ~2126 bit decimal number.
*/
#define _PY_LONG_MAX_STR_DIGITS_THRESHOLD 640
#if ((_PY_LONG_DEFAULT_MAX_STR_DIGITS != 0) && \
(_PY_LONG_DEFAULT_MAX_STR_DIGITS < _PY_LONG_MAX_STR_DIGITS_THRESHOLD))
# error "_PY_LONG_DEFAULT_MAX_STR_DIGITS smaller than threshold."
#endif
/* runtime lifecycle */
extern PyStatus _PyLong_InitTypes(PyInterpreterState *);
extern void _PyLong_FiniTypes(PyInterpreterState *interp);
/* other API */
#define _PyLong_SMALL_INTS _Py_SINGLETON(small_ints)
// _PyLong_GetZero() and _PyLong_GetOne() must always be available
// _PyLong_FromUnsignedChar must always be available
#if _PY_NSMALLPOSINTS < 257
# error "_PY_NSMALLPOSINTS must be greater than or equal to 257"
#endif
// Return a borrowed reference to the zero singleton.
// The function cannot return NULL.
static inline PyObject* _PyLong_GetZero(void)
{ return (PyObject *)&_PyLong_SMALL_INTS[_PY_NSMALLNEGINTS]; }
// Return a borrowed reference to the one singleton.
// The function cannot return NULL.
static inline PyObject* _PyLong_GetOne(void)
{ return (PyObject *)&_PyLong_SMALL_INTS[_PY_NSMALLNEGINTS+1]; }
static inline PyObject* _PyLong_FromUnsignedChar(unsigned char i)
{
return Py_NewRef((PyObject *)&_PyLong_SMALL_INTS[_PY_NSMALLNEGINTS+i]);
}
PyObject *_PyLong_Add(PyLongObject *left, PyLongObject *right);
PyObject *_PyLong_Multiply(PyLongObject *left, PyLongObject *right);
PyObject *_PyLong_Subtract(PyLongObject *left, PyLongObject *right);
int _PyLong_AssignValue(PyObject **target, Py_ssize_t value);
/* Used by Python/mystrtoul.c, _PyBytes_FromHex(),
_PyBytes_DecodeEscape(), etc. */
PyAPI_DATA(unsigned char) _PyLong_DigitValue[256];
/* Format the object based on the format_spec, as defined in PEP 3101
(Advanced String Formatting). */
PyAPI_FUNC(int) _PyLong_FormatAdvancedWriter(
_PyUnicodeWriter *writer,
PyObject *obj,
PyObject *format_spec,
Py_ssize_t start,
Py_ssize_t end);
PyAPI_FUNC(int) _PyLong_FormatWriter(
_PyUnicodeWriter *writer,
PyObject *obj,
int base,
int alternate);
PyAPI_FUNC(char*) _PyLong_FormatBytesWriter(
_PyBytesWriter *writer,
char *str,
PyObject *obj,
int base,
int alternate);
#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_LONG_H */